And Digits is here to keep a running tab of what’s taking off and what’s fading away.

For the past few weeks, Digits has published a weekly feature called App Watch, which highlights a particularly buzz-worthy app.

The Journal today launched a new series, The Business of Apps, dedicated to tracking the industry’s economics — and along with that, to identify the winners and losers.

Each week on App Watch, Digits will highlight an app that’s rising in the App Store rankings or is attracting a high amount of attention.

Previous apps featured in App Watch include Snapchat, an app that’s taking off among teens, and Minecraft, one of the most profitable apps in the App Store.

We include metrics from AppData that tracks the rise and fall of these apps. The goal is to give a constant play-by-play of the leaders in the the highly competitive app ecosystem — and surface some apps that are worth downloading, if only for the sake of killing a few hours.

Here’s a collection of all the apps featured in App Watch so far. Be sure to check out Digits each week for a new app: